The semiconductor integrated circuit (IC) industry has experienced exponential growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs. Such scaling down has also increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed.
For example, light diffraction in an optical lithography system becomes an obstacle for further scaling down the feature size. Common techniques used to decrease the light diffraction impact include using optical proximity correction (OPC), a phase shift mask (PSM), and an immersion optical lithography system. A fracture is performed on an IC design layout feature making a mask after the OPC during. The fracture may be executed at asymmetrical dissection points of the IC design layout feature. However, small fragments are created by the asymmetrical dissection points. Therefore mask fidelity is degraded by the small fragments and further mask performance is impacted.
Accordingly, what is needed is a method to improve the OPC to reduce number of the small fragments after performing the OPC to an IC design layout data.